Work of a shrimp?(fridmani missing fin overnight)

[E-A-G-L-E-S]

I am wondering who or what is the likely culprit in the semi circle section of fin missing from my Fridmani. If it is a mantis or pistol it must be a small guy as I have no crannies worth a lick that I can't see in my rock and this rock has been only damp and out of a tank 2x for over 12hrs in the last 60 days.
He was whole finned yesterday.
It appears to be a U but turned on its' side, pretty surgical looking, bite/claw.
Soory for the camera and my skills.

 

[IFbettas]

What other fish are with it?

Honestly, it's no big deal. It should be completely healed up within a week. Things like that just happen sometimes.

 

[E-A-G-L-E-S]

Yellow coris
lined chromis
2x ocellaris